1. Field of the Invention
The invention relates in general to a light emitting device and a manufacture method thereof, and more particularly to a light emitting device with a light source disposed on a circuit board and the manufacture method thereof.
2. Description of the Related Art
If a light emitting diode (LED) element is used as a light source in a backlight module, the LED element is normally soldered on a circuit board to form a lighting bar. The lighting bar is further incorporated with other optical elements and is disposed in the backlight module. The backlight module is classified into an edge type backlight module and a direct type backlight module according to a light-emitting surface of the light source.
Let an edge type backlight module be taken for example. For the convenience of the assembly and operation of the edge type backlight module, power lines for inputting an external power are disposed at the same side of the edge type backlight module. As a result, circuit boards soldered with LED elements need to have two different forms. Although according to the design of a linked board diagram, the circuit boards of different forms can be formed on the same linked board. However, the number of the circuit boards formed on the linked board is limited to be even, hence increasing the manufacture cost.
In addition, if LED elements comprise chips of three colors, for example, red, green and blue, the arrangement of the chips in the same kind of the LED elements is the same. Referring to FIG. 1, a perspective of a direct type backlight module is shown. The direct type backlight module 100 comprises a plurality of circuit boards 110. Each of the circuit boards 110 has a plurality of LED elements 111 in the same form. The LED elements 111 are used as light sources of the direct type backlight module 100.
As the LED elements 111 herein are in the same form, the arrangement of the chips of three colors in the LED elements 111 is the same. That is, the arrangement of the chips is a red chip 112, a green chip 113 and a blue chip 114 in order. As illustrated in FIG. 1, under such arrangement, a particular color tends to be over-concentrated in a certain direction.
Thus, when the direct type backlight module 100 is in use, several color bands are formed by over-concentrated colors, hence affecting display qualities. Although the above problem can be avoided through the design of different circuit boards, the circuit boards on the same linked board are still subjected to the above limitation that the number of the circuit boards has to be even.